Initialize the Query

To initialize a query, call
LoaderManager.initLoader(). This
initializes the background framework. You can do this after the user has entered data that's
used in the query, or, if you don't need any user data, you can do it in
onCreate() or
onCreateView(). For example:

// Identifies a particular Loader being used in this component
private static final int URL_LOADER = 0;
...
/* When the system is ready for the Fragment to appear, this displays
* the Fragment's View
*/
public View onCreateView(
LayoutInflater inflater,
ViewGroup viewGroup,
Bundle bundle) {
...
/*
* Initializes the CursorLoader. The URL_LOADER value is eventually passed
* to onCreateLoader().
*/
getLoaderManager().initLoader(URL_LOADER, null, this);
...
}

Start the Query

As soon as the background framework is initialized, it calls your implementation of
onCreateLoader().
To start the query, return a CursorLoader from this method.
You can instantiate an empty CursorLoader and then use its
methods to define your query, or you can instantiate the object and define the query at the
same time: